1. Field of the Invention
This invention relates to a fuel supply device for supplying fuel from a fuel tank to an external device.
2. Description of the Related Art
Japanese Laid-Open Patent Publication No. 2005-155602 discloses a fuel supply device. This fuel supply device comprises a cover for closing an upper opening of a fuel tank, two guide members extending in an up-down direction in the fuel tank, and a fuel discharging unit guided by these guide members so as to be vertically movable within the fuel tank. A spring is disposed between the fuel discharging unit and the cover. The spring biases the fuel discharging unit toward the bottom surface of the fuel tank. Therefore, the bottom of the fuel discharging unit is in contact with the bottom surface of the fuel tank. The fuel discharging unit draws fuel in from the fuel tank through an inflow port formed in the bottom part of the fuel discharging unit, and discharges the drawn fuel outside the fuel tank. The fuel discharging unit can thus draw the fuel in the fuel tank through the inflow port even if the level of fuel in the fuel tank becomes low. The cover includes a storage chamber that stores a control unit for controlling the fuel discharging unit and a cooling passage formed adjacent to the storage chamber. When the fuel discharging unit is operating, part of fuel discharged from the fuel discharging unit flows through the cooling passage in order to cool the control unit.